A Bit of New Evidence on Drowning

March 5, 2015 careflightcollective 3 Comments

An opportunity for a quick post to point to a new publication with something useful on drowning. From Dr Alan Garner.

Unfortunately we attend a number of paediatric drownings in the Sydney area every year. Many recover well. Some do not. Some do unexpectedly well. We have had a patient who was GCS 3 at our arrival and asystolic on the monitor make a full recovery. Most children in this situation however either die or are severely impaired.

This brings us to a vital question – when is it reasonable to stop resuscitation? Well, here’s some evidence to help inform the chat.

The Dutch Study

Over at the BMJ a new paper has just hit the screen:

Outcome after resuscitation beyond 30 minutes in drowned children with cardiac arrest and hypothermia: Dutch nationwide retrospective cohort study.

This study is a nationwide observational study in the Netherlands of children with cardiac arrest due to drowning. The authors have put together ten years of data collected in a country with more than 30 million people. It seems unlikely we’ll see a bigger study.

The study indicates that no child resuscitated for more than 30 minutes had a good outcome. There were good outcomes in those resuscitated for less than 30 minutes.

This matches our experience. Our patient with the GCS 3/asystole combination and a subsequent good outcome had a return to spontaneous circulation while still on scene.

The other point of interest is that it is from an environment where water temperature is presumably a fair bit colder than the coastal fringes of Australia, but the results would appear to be similar.

It would appear that discontinuing resuscitation after 30 minutes in those with no neurological improvement or stuck in asystole is a reasonable practice.

It still comes down to time.

Paediatrics

Revisiting Old Stories About Little Airways

February 12, 2015 careflightcollective 5 Comments

Dr Andrew Weatherall returns to stuff about paediatric airways, a bit of a companion to an earlier post with some practical tips.

There are some things you’re taught from a very young age to believe in. Then it turns out it’s just plain wrong. Santa Claus. The Tooth Fairy. The Public Holiday Numbat. (Well, the last one might be specific to my upbringing.)

And in medicine there are plenty of examples those too. Oxygen is always good. You can’t manage trauma without a cervical collar. Then of course there’s pretty much everything about the paediatric airway. As if managing kids didn’t come with challenges anyway, we all get to work with information that is just plain wrong.

And there’s no mistaking that clinicians find paediatric airways difficult. The staff from Royal Children’s Hospital Melbourne have recently published a sizeable prospective study of emergency department intubations. This is from a big, clinically excellent tertiary kids’ hospital receiving 82000 patients in their ED every year. In 71 intubations across a year (only 71!), 39% had adverse events (most commonly hypotension in 21% and desaturation in 14%) and the first pass success rate was 78% (only 49% had a first pass intubation with no complications).

Now lots of things will contribute to those figures. But at least part of pondering that has to be making sure we understand what we’re dealing with.

"Please, go on" says Public Holiday Numbat [unchanged via quollism on flickr under CC] — “Please, go on” says Public Holiday Numbat [unchanged via quollism on flickr under CC]

Old Truths

Some old historical truths are harder to pull away than a spider web stuck to a bear with superglue. There’s a recent review that appeared in Pediatric Anesthesia written by Dr J Tobias which steps through some of this dogma.

It points out that some of the classic teaching on the paediatric airway come out of a 1951 report by a Dr Eckenhoff. This includes the issues of the position of the larynx, the shape of the epiglottis and the funnel-shaped airway. Actually, to really trace the story, you have to start a little earlier.

Stepping Back

It’s 1897. Waistcoats aren’t ironic yet. Pipes aren’t an affectation they’re an expectation. Jack the Ripper is part of shared memory, not fevered historical narratives. And Bayeux was making casts of the airways of dead children. 15 casts actually in kids aged 4 months to 14 years.

Taking measurements of the circumference of the airway at the glottis, cricoid level and trachea, the cricoid ring was noted to be narrower than other parts of the airway (the topic of the shape of the airway wasn’t mentioned). This is the work that led to the idea that kids under the age of 8 had a conical larynx, with the cricoid ring as the narrowest point.

Consider for a second the qualities of plaster poured into a distensible tube. Wait, it’s not entirely distensible because the cricoid can’t distend. Is it maybe possible that the plaster may have distorted the anatomy? I’ll leave that with you for a bit.

This suggestion of the conical airway made its way into Eckenhoff’s later paper (though with a specific note that cadavers may not represent the living accurately). There were also some descriptive points raised:

The larynx moves down from the C3-4 level in the neonate to C4-5 in the adult (I’ve always been under the impression this move is brought about both by the need to phonate properly for speech and the loss of the need to breathe and breastfeed at the same time, but this point doesn’t feature in airway descriptions and I’m happy to be corrected).
A stiffer and more “U” or “V”-shaped epiglottis with an angle to the anterior pharyngeal wall of around 45 ⁰ rather than lying close to the base of the tongue.
A case report of a 2 year old with airway complications thought to be related to an inappropriately sized tube, feeding the idea of uncuffed endotracheal tubes in kids under the age of 8.

All these points that form part of so much teaching lead to another question – would such a descriptive effort get a run in modern publishing?

Newer Tools Means Better Understanding

The answer of course is probably not. Of course you can only use what you have and it’s absurd to judge Eckenhoff (or Bayeux) for their accuracy against modern modalities. All we can do is revisit our thinking when new information becomes available.

We now have the significant advantage of radiological techniques (CT or MRI) and bronchoscopy to evaluate airways in children who aren’t dead. Again the Tobias article goes into more details but there are some key things to take from this modern literature:

In spontaneously breathing and muscle relaxed patients, the cricoid was not the narrowest part of the airway. That honour belongs to the vocal cords.
There is no change in the ratios of the cross sections over age – the cricoid doesn’t start relatively smaller and enlarge by the time you hit 8.
The cross-section looks like an ellipse (there’s more distance between the anterior and posterior bits than the two side bits).

What should we do then?

Well for starters we should probably settle the tube choice thing. This is just more support for the argument to use a cuffed tube. For starters, the old “leak” test seems pretty dubious when you could be snug against the lateral walls but still leaking around the anterior or posterior areas. And I’m guessing no one has had their “leak accuracy assessment” externally audited.

It makes more sense to use an appropriately sized cuffed tube with the cuff pressure kept < 20 cm H₂O. There’s now fairly convincing evidence that appropriately used cuffed tubes don’t cause big issues in recovery. Better ventilation, better monitoring, less flows and gentler tube material in contact with the mucosal wall. Makes sense.

What you can’t do is ignore the cricoid. It is still an unyielding bit of the anatomy and anyone can turn a high volume-low pressure cuff into a high volume-high pressure cuff – the difference is a couple of mL. And swelling in an airway that starts with a much smaller cross-sectional airway still means less margin for flow obstruction.

So choose the right tube, use it safely and you can get on with things.

While We’re At It, Let’s Forget One Blade to Rule Them All

Seeing as we’re talking about things that aren’t things, you may have also come across the idea that you should use a straight blade for the smaller kids (say, kids under 2). I’ve mentioned elsewhere that I think this is baloney but here’s a little bit of evidence.

Varghese and Kundu have published something on exactly this issue. 120 kids aged from 1-24 months had laryngoscopy (once anaesthetised and given muscle relaxation) with either a Miller or Macintosh blade, and then crossed over to the other type of blade. (Note they used both with the tip in the vallecula.)

The findings? The views were pretty much the same. The rates of difficulty were about the same. In fact, it’s a pretty beige set of numbers where being beige is actually as cool as things could be.

Some where the view wasn’t so great with a Macintosh had a better view with the Miller blade. Some went in reverse. The message though is a pretty resounding “same, same”.

So there’s just some truths that needed revisiting. There are no funnel-shaped airways. The airway isn’t round. There’s not one correct blade for the under 2s.

I still resent having to give up on the Public Holiday Numbat though.

References:

Here are the PubMed links for those mentioned in this post.

Long E, Sabato S, Babl FE. Endotracheal intubation in the pediatric emergency department. Pediatric Anesthesia 2014;24:1204-11. doi: 10.1111/pan.12490

Tobias JD. Pediatric airway anatomy may not be what we thought: implications for clinical practice and the use of cuffed endotracheal tubes. Pediatric Anesthesia 2015;25:9-19. doi: 10.1111/pan.12528

Varghese E and Kundu R. Does the Miller blade truly provide a better laryngoscopic view and intubating conditions than the Macintosh blade in small children? Pediatric Anesthesia 2014;24:825-9. doi: 10.1111/pan.12394

Education

Why? How? What? Big Questions for Prehospital Simulation

January 29, 2015 careflightcollective 6 Comments

At CareFlight another round of training many people is about to come up so it seemed like a good chance to ask Dr Sam Bendall for her first contribution.

Sam is an Emergency Physician who is passionate about education, particularly all things simulation. She works half-time at Royal Prince Alfred Hospital in Sydney in the Emergency Department where she helped develop and teaches the RPA Trauma Team Training program, teaches on the CIN nurses programs and helped develop the ED Essentials program.

At CareFlight she is a retrieval doc (the other half-time) and the Deputy Director of Education. The CareFlight Education Team are always up to interesting things – from training the Australian Defence Force medical on how to look after all things ballistic, medical, surgical and paediatric, to running the Pre-Hospital Trauma Course both in Sydney and other locations (Malaysia, anyone?), to running Trauma Care Workshops all over the country. Oh, and of course all those working with CareFlight too.

Anyway, here’s Sam …

As a passionate advocate for simulation I look around and see this amazing tool appear in many guises, all under the same blanket term. It certainly seems to mean many things to many people depending on their previous experiences. In some ways it is the SWISS ARMY KNIFE of kinesthetic education. The coolest knife has pliers and scissors. However, just like a Swiss army knife, it can be a harmful weapon (hence the name!), just plain useless (like when you want the one with pliers but you only have the single blade), or a bit uninspiring and encourage automatic behaviours – e.g. all Swiss army knives are red and you should have one.

This clearly rubbish version doesn't even have the magnifying glass. — This clearly rubbish version doesn’t even have the magnifying glass.

Simulation has almost become the learning apparatus du jour – everyone has to do it but some are not sure why or how to really make it work. A bit like having a Swiss army knife so you can be part of the Swiss army, but it lives in the drawer.

I will put a disclaimer in at this point. The following are my own opinions – the musings of a dedicated simulation-phile after several years of training in simulation and doing simulation exercises for anywhere from 2 – 150 people.

So what’s the point?

I’m going to put a slightly different spin on it, with an emphasis on simulation for the pre-hospital environment. Simon Sinek, in his TED talk in 2009 titled “Start with Why” made a very powerful case for asking yourself WHY you want to do something… in this case, simulation, at the outset. The HOW and the WHAT will follow if you drill down onto the why and firmly establish WHY you want your participants to do simulation.

Simulation is a journey, for both the instructors and participants. Hopefully a journey towards some constructive learning, but one that will have many interesting twists and turns along the way. Being sure of WHY you are undertaking this part of the journey, gives you the freedom to explore the twists and turns of the journey without losing sight of the original intent. So my step 1 in building a simulation, is to ask yourself why? WHY are you doing this?

In our organisation, our WHY? is to create a mission-ready workforce.

Pre-hospital medicine throws out so many variables – communication, teamwork, environmental, situational awareness, medical challenges, geographical challenges and the list goes on.

In order to make our workforce mission ready, we need them to be critical thinkers, able to choose the right skill, equipment and approach for the right case at the right time.

Though if we had one of those shapeshifting Terminator ones could we program it to be friendlier?

We also need them to be aware of the variables they will need to deal with on real jobs so that they can manage them consciously. In order to do this we need to replicate as many of these variables as possible so they can address them in a training environment. We aim to send our participants out on jobs that feel just like the scenarios they have done in training. No pressure!

HOW? – choose your weapon…

The simulation menu is fairly extensive and limited only by your creativity and ability to structure it in a way that is true to the learning objectives and easy to follow for your participants. The key elements of creating a scenario, whether it be for 2 or 50 participants, is that they need to know the rules, boundaries, and premises for the scenario….. hmm sounds like parenthood!

So first decide on your structure. Is it an audience that is learning a concept for the first time and you need to do it for real, but slow it down? Well “pause and discuss” is your man. Do you need to see where your participants’ critical decision making is at and where the deficits lie? Immersive, relatively high fidelity simulation, with key variables built in, is the tool of choice.

Do you need to occupy 30 participants in a large scale simulation? – Create foci so the participants will need to form their own teams within the simulation. This will bring out all of the teamwork, communication and leadership points from the start.

Whatever weapon you choose, it needs to be appropriate to the audience, their experience and what you are trying to teach by doing the simulation exercise.

WHAT …the final frontier

Well this depends on what you are trying to deliver in your simulation. If, for example, your aim is to test and consolidate a new protocol, then the scale of your simulation can be quite limited. You may not need to bring in as many variables, or much fidelity. As long as the key prompts are there for the participants and they have the knowledge, skills and equipment to fulfill the protocol, then a limited scenario is fine.

BUT…. and there is a BIG but in this one. Be realistic in developing your scenario. If you are testing an ALS protocol, doing a bog standard ALS protocol with a patient in a bed may tick your box. BUT ….. in 20 years of medicine I think I have been to less than 10 arrests in ward beds and way more than 30 in other places – the toilet, the CT scanner, theatre, the foyer of the hospital, the waiting room, the beach etc. etc. You get the picture. So I would argue here that a bog standard ALS type scripted scenario has its place, but should be followed up by the application of the protocol where it is likely to happen and bring in the teamwork and communication aspects that we know actually make ALS protocols work in real life.

At CareFlight we educate using a “crawl, walk, run” paradigm.

First you crawl – i.e. you learn the skill or concept in isolation.
Then you walk – using relatively low fidelity simulation with limited learning outcomes, you learn to apply that skill appropriately.
Then you RUN. In our “RUN” scenarios, we introduce many more variables that replicate the environment they will have to operate in. We increase the fidelity and prompt the participants to evaluate the situation, decide whether that skill or concept is appropriate, apply it if it is or find an alternative if it is not. This layering approach helps to consolidate skills and knowledge and develops critical decision-making processes in a way that is directly applicable to the job we do.

When you get to the RUN scenario you are trying to bring out multiple learning points across many categories, for example:

Teamwork and communication (CRM)
Leadership skills (CRM)
Graded assertiveness and conflict resolution (CRM)
Scene safety and situational awareness (CRM, environmental and logistics)
Management of a multitrauma patient in an isolated environment (medical)
Packaging and preparation for transport (logistics, medical)
How to carry a patient out of the bush safely (logistics, medical)
Planning for contingencies e.g. weather etc. (logistics)

Then the scenario has to be much higher fidelity and be crafted in a way that replicates those key learning objectives – CRM, medical, environmental and logistic. You need to recreate the key environmental elements that will impact on the participants’ decision-making, bring in the key teamwork elements, replicate the equipment or types of equipment they will use and think about the team structures they will be given. Even simple tweaks to the scenario such as limiting access to the patient’s head, can improve the problem solving and CRM elements of the scenario so the devil is very much in the detail here. AND SO IS THE FUN …

Why yes that is a mobile rollover simulator that some clever people built ... — Why yes that is a mobile rollover simulator that some clever people built …

Prehospital Trauma

A Short Video About Bleeding Airways

January 16, 2015 careflightcollective 4 Comments

Managing the airway in prehospital and retrieval medicine is a challenge and has inspired many a discussion in many a setting. And anyone working in the area would appreciate the additional challenge when there’s lots of blood getting in the way. As a result everyone has tips and and tricks to try and manage things.

This is by no means the first time people have come up with an approach (or shared an approach) but in the spirit of wide-ranging discussion, here’s a suggestion from Dr Alan Garner recorded for posterity in video.

It runs for about 10 minutes and you’ll note that at the end there’s an update as the approach evolved.

All thoughts, feedback and experience very welcome.

Retrieval

Keeping Things Calm: Remote Retrieval of the Psychiatric Patient

January 4, 2015 careflightcollective 24 Comments

Jodie Mills, RN works with CareFlight’s Top End Medical Retrieval Service, flying out of Darwin across vast stretches of the Northern Territory. She grew up in the Royal Melbourne Hospital ICU before moving to Darwin 8 years ago where she completed midwifery studies. She joined CareFlight 4 years ago and slightly pities all those who don’t get to fly in the top end.

When asked to contribute to a blog and write about psychiatric aeromedical retrieval all I heard was my colleagues’ collective signs of “not another psych job!!”

The thing is, I’ve developed a bit of an interest in these patients after closely looking at the psychiatric retrievals in NT for the last 3 years. This specialised patient group presents a huge challenge to both the flight crew and our remote colleagues when presenting acutely unwell in our communities.

By the Numbers

I recently presented at the ASA/FNA/ASAM Aeromedical Retrieval Conference in Brisbane. I thought maybe we had a few psychiatric patients but I quickly realised after my presentation that the number of psychiatric retrievals we undertake in the top end is well above average i.e. its extremely high (15% of our total missions).

From Feb 2012 to the 20^th October 2014 we retrieved 651 psychiatric patients, averaging 22-24 per month – it’s an almost daily occurrence. Demographically the patient population remains consistent with approx. 90% of patients Indigenous Australians, with male to female ratio if 1.45:1. The mean age is 31, however our youngest was 12, our oldest being 74 years.

We have only intubated 3% of this population which has led to expedited admission to the singular psychiatric facility at Royal Darwin Hospital (RDH). The inpatient psychiatric ward at RDH has a catchment area of 700,000 square kilometres.

It’s Not Just a Local Thing

Mental illness throughout the world is on the increase with the WHO (2014) predicting mental illness to be second only to cardiovascular disease for burden of disease by 2030. The stigma associated with mental health issues remains the greatest obstacle to such patients accessing appropriate care. This stigma may be even more pronounced in remote Indigenous communities. Drug induced psychosis, predominantly cannabis (397 patients), followed by suicidal ideation/ hanging (224) were the most common diagnosis with the remaining patients having bipolar, mania or behavioural disturbances.

At the ASA conference I asked my aeromedical peers “How do you transport your psychiatric patients?” the answer was “we don’t, they go by road”. I quickly realised then that CareFlight and other retrieval services working in truly remote areas provide a unique service.

The Perfect Storm

We all know too well the challenges involved in the aeromedical transport of compliant patients who are unwell. However if we add delusions, hallucinations, physical aggression a tendency to physical violence and homicidal thoughts into the mix we have a potential aviation disaster on our hands. These are the just some of the symptoms the majority of our psychiatric patients display when referred to CareFlight. We then face the task of transporting such patients in a small aircraft where we will place seatbelts and wrist and ankle restraints on them, we will sit approximately 50cm away from them and the tell them they cannot smoke, they cannot go to the bathroom, they cannot eat or drink. I can’t imagine how stressful this must be for a patient that is already thought disordered.

What We Do

The biggest challenge for the aeromedical clinician is assessing the need and amount of sedation that will be required for safe retrieval of the acute psychiatric patient. If we have learnt anything it is definitely that “one-size DOES NOT fit all” when it comes to choosing sedative combinations to safely retrieve acute psychiatric patients. However we have found that pre-flight sedation with an atypical antipsychotic (olanzapine) and a sedative (diazepam) is of the utmost importance. As we become better skilled at treating psychiatric patients we have increased the pre-sedation (Olanzapine & Diazepam up to 20mg oral) which seems to be decreasing inflight sedation requirements. This enables the psychiatric patient to be admitted to the appropriate ward in a timely manner.

Top Tips for What to Do:

Start sedation early:

As mentioned above, premedication prior to retrieval is vitally important. In most cases an antipsychotic (Olanzapine 10mg) and a benzodiazepine (Diazepam 10mg) is the premedication of choice. However, acute psychiatric patients presenting with drug induced psychosis (be it first or subsequent presentations) routinely require up to 20mg- 30mg of both Olanzapine and Diazepam orally. The first dose of sedation is given prior to the crew departing Darwin and then half an hour prior to the crews landing at the communities/ regional hospitals. This administration is overseen by the Medical Retrieval consultant (MRC) on duty. If the patient is not responding to the Olanzapine and Diazepam, the likelihood of requiring in-flight sedation is increased as is the probability of intubation for transport.

In-Flight sedation:

We find in flight we tend to use midazolam, propofol and ketamine. The drug of choice is directly related to the flight doctor’s area of expertise. The ED Registrars tend to use midazolam and ketamine, whereas the ICU and Anaesthetic registrars head for the propofol and midazolam.

On arrival at the referral centre the patients are assessed for the need for further sedation prior to flight.

Pre-Flight Sedation: Midazolam 2-5mg IV
In-flight Sedation:
- Propofol Infusion 0.2-0.5mg/kg/hr and titrate as required
- Ketamine Infusion 0.5-1mg/kg/hr and titrate as required

A Richmond Agitation Sedation Scale (RASS) of -3 (Moderate) to -4 (Deep) or a Ramsey Sedation score of 5 indicates the level of sedation required for safe transport.

The ability to discontinue the sedative and allow the patient to wake prior to admission at the receiving centre is extremely important. If the flight crew are able to deliver an acute psychiatric patient to the receiving centre awake and ready for assessment this expedites the patients’ admission to the in-patient facility from the emergency department or, optimally allows for direct entry into the inpatient facility at the receiving centre.

Richmond Agitation Sedation Scale:

Ramsey Sedation Scale:

Managing the environment:

Managing the stressors of flight is extremely important when retrieving an acute psychiatric patient. Using ear plugs, blankets to keep patients warm, positioning for comfort when heavily sedated, limiting cabin conversation and ensuring physical restraint are fastened appropriately ensures the acute psychiatric patient does not experience any extraneous stressors throughout their flight.

Local law enforcement:

On occasion the local law enforcement will be involved with the acute psychiatric retrieval. The resource poor environment of the community clinic necessitates the presence of police to help control patients as documented under the section 9.

Coordination:

The coordinating Medical Retrieval Consultant will liaise with the Consultant Psychiatrist on call at the hospital, alerting them to the impending admission. The Consultant Psychiatrist then coordinates with their in-patient team to ensure timely assessment of the patient if they are to be admitted through the emergency department.

Although the collective groan when another psychiatric retrieval arises resonates through the base we remain steadfast in our support to our rural and remote colleagues and we will continue to play a vital role in maintaining safety of the community, the families and the patients who are all touched by mental illness in the top end of the NT.

Paediatrics, Prehospital Trauma

DIY to Stop the Blood

December 18, 2014 careflightcollective 3 Comments

This thing comes from Dr Andrew Weatherall, paediatric anaesthetist and prehospital doc. He also blogs over at www.theflyingphd.wordpress.com

I don’t do DIY. This is partly because in the same way I wouldn’t expect a carpenter to have a crack at fixing their kids’ bones in preference to seeing an orthopod, I think it makes sense to use professionals.

It’s also because I’m just not that great at it. Anything I did make would end up looking like something trying to squeeze itself into the shape of the thing it is sort of supposed to be. And I’m fond enough of my family to want to protect them from the risks of my own handiwork.

Here's one I prepared earlier (via CC and flickr user mhlradio) — Here’s one I prepared earlier (via CC and flickr user mhlradio)

Anyway, I do paediatric anaesthesia. I get to spend more than enough time trying to make things that aren’t quite right for the situation fit in with what I need. Why DIY at home when you have to DIY at work?

Making Things Fit

The problem with paeds practice is that kids are sometimes kids and sometimes little adults and often forgotten in research. Or if not forgotten put in the category of “the ethics and logistics of that will be so painful I’d rather remove my spleen via my auditory canal”. And in trauma care we’re also dealing with total numbers that are lower than is the case for adults.

So what we end up with is lots of extrapolation from adult data and lots of retrospective studies sprinkled with the occasional fairy dust of a small case series. Then we have to try and mash those leftovers together to come up with a plan for a very specific situation.

An example: how about tranexamic acid in trauma?

Making It Up

Following on from CRASH-2 and MATTERs, what to do in the younger generation is an obvious question. A big prospective study in kids after trauma would be perfect. And a pipe dream.

So if you turn to the literature what you see is a large number of people trying out archery on summer camp and hitting many, many different targets while all shooting vaguely in the same area.

To corral some of them in one spot, take the review by Faraoni and Goobie looking at antifibrinolytics in non-cardiac surgery in kids. All of the following values are listed as loading doses in the scoliosis and craniofacial groups: 10, 15, 20, 50, 100 and 1000 mg/kg with infusions anywhere from 1 mg/kg/hr up to 100 mg/kg/hr. In the scoliosis patients there are total numbers of up to 80 patients and slightly baffling figures suggesting total blood loss is decreased but transfusion requirement pretty much the same. Or that in the craniofacial surgery group it seems like probably there might be slightly less blood loss and transfusion needs.

But in paediatric cardiac surgery there might be more seizures too, even though the overall safety profile looked pretty good. Nothing definitive though. Such clarity.

So now the job is to consider how to take this magnificently imperfect evidence and apply it to a specific and different clinical scenario, trauma.

Go.

The Pragmatist

The Royal College of Paeditrics and Child Health and the National Paediatric Pharmacists Group Joint Committee had exactly this challenge back in 2012. It’s the intellectual equivalent of trying to catch pancake batter. Messy.

Ultimately they chose what they termed the pragmatist’s option – 15 mg/kg loading (up to 1 g) over 10 minutes then an infusion of 2 mg/kg/hr. Maybe enough to do something, but with a homeopathic infusion so you were unlikely to get complications. Entirely rational in the absence of evidence too.

But what if there was another approach?

Another Way

What they didn’t have access to was some recent data out of the UK military Afghanistan experience in Camp Bastion. TXA had become standard for adult trauma patients under certain conditions after the release of CRASH-2 and both editions of MATTERs. These sort of treatment centres don’t just receive adults though and they must have been wrestling with what to do in smaller patients.

What they describe is another type of pragmatic approach. Rather than any adjustment they just did what they were already doing. Tranexamic acid in a 1 g dose for all comers and more on the basis of medical assessment (though it looks like no one got another dose).

This gets past lots of problems, particularly with getting accurate weights or ages and the need to learn different treatment regimes. It also comes with a certain amount of glee, not because you’re sort of saying “kids are just little adults” and you know that would break plenty of people. You’re actually saying “kids are adults”. If you say that 3 times while drawing a pentagram in a circle of candles, somewhere a paediatrician will be woken with a pain between their shoulder blades.

They describe a breakdown of 66 patients under 18 getting TXA and 700 without TXA. Having severe abdominal or extremity injuries and showing evidence of severe metabolic acidosis were significant predictors that TXA would be used. TXA use was independently associated with reduced mortality but no great difference in packed red blood cell/fresh frozen plasma transfusion ratios. Intriguingly in those getting a large volume transfusion, receiving TXA was associated with greatly improved neurologic status at the time of discharge (now that opens up a need for more work). They didn’t note an increased risk of thromboembolic complications (but they probably don’t have the numbers to be sure about that).

Overall, we’re talking about kids with an average age of 11 so using the equation of (3 x age) + 7, the weight might be about 40 kg (though I’m not certain if the weights might be a bit less than algorithms from developed countries). That would mean a starting dose averaging round 25 mg/kg.

The Other Extra Bit

That 2014 review also mentions an additional titbit that’s a little useful. Some pharmacokinetic work has been done in patients with craniofacial surgery patients and it appears that an upfront dose of 10 mg/kg then an infusion of 5 mg/kg/hr is optimal for establishing appropriate drug levels. This is far more useful information than cardiac surgery pharmacokinetics where additional considerations of dilution by bypass circuits, potential for pre-existing cyanosis and a variety of other factoids make it hard to draw comparisons. So 10 mg/kg might be enough initially but the subsequent infusion should probably be more than a scattering of holy water (as in more than 2 mg/kg).

The Bottom Line

We’re still stuck with not enough information about paediatric patients. Will there be a bigger study in paeds trauma soon? Probably not. But we can say with more confidence than before that doses that are pretty big seem to be OK.

So what would I do now? I’d modify the pragmatic plan and go with a 20 mg/kg loading dose (or 0.2 mL/kg of our current stock) and once in hospital I’d go with an infusion of 5-10 mg/kg/hr.

And I’d still hope someone is going to try to build a better shack.

References:

Are you after that review? It’s Faraoni D and Goobie SM. The Efficacy of Antifibrinolytic Drugs in Children Undergoing Noncardiac Surgery: A Systematic Review of the Literature. Anesth Analg 2014;118:628-36.

Or maybe the RCPCH statement on using TXA in trauma – try here.

And here’s the Pubmed listing for the newer trauma study – Eckert MJ, Wertin TM, Tyner SD et al. Tranexamic acid administration to pediatric trauma patients in a combat setting: The pediatric trauma and tranexamic acid study (PED-TRAX). J Trauma Acute Care Surg. 2014;77:852-8.

And in case you didn’t have it already, here’s the spot for the [(3 x age) + 7] calculation. Luscombe MD, Owens BD, Burke D. Weight estimation in paediatrics: a comparison of the APLS formula and the formula ‘Weight = 3(age)+7’ Emerg Med J 2011;28:590-3.

International

Thoughts from the Control Tower

December 3, 2014 careflightcollective 7 Comments

This is the first of what we hope will be a series of posts from Dr Paul Bailey who works as a Medical Director for CareFlight International Air Ambulance. Paul will try to provide insights into the challenges of managing retrievals across oceans. Here’s the starter.

In his real life, Paul Bailey is an Emergency Physician based in Perth, Western Australia who dabbles in the Greyhound racing industry (having owned 10 dogs and never been to the track). He can often be found in the outer at an Aussie Rules football oval, most commonly critiquing the performance of the umpires in an entirely constructive manner. Past lives include a molecular biology PhD – in Jellyfish venom – don’t ask – and being a glassy in various drinking establishments in Western Australia.

Paul has previously undertaken international retrievals, helicopter work supporting Australian Army exercises and time with Queensland Rescue at Cairns. He now makes cameo appearances on the International Medical Director roster, as a medical director for retrievals in the NT and the Inpex oil and gas business.

If you’ve decided to be involved in retrieval, why think local when you can think global? After many years of toiling through school, then medical school, and then advanced training in the acute care specialty of your choice, you’re now in the hot seat ready to go.

Living the Dream

You’ve always fancied yourself as an airborne medico ever since you sat on your Dad’s knee watching “The Flying Doctors” in the late ‘80s and thinking how cool that would be. Truth be told, you also liked Top Gun and from time to time have drawn a laugh with the immortal line: “Negative Ghostrider, the pattern is full.” But you still buzzed the control tower anyway.

Or perhaps more likely you rode that little bit too close to your Mum on your BMX. You’ve also heard, along the way that everyone in retrieval gets a nickname and you’re tossing up between Maverick and Goose.

And it’s safe to say you have bought the Ray Ban Aviators already.

Living the Reality

So what’s it really like? Different to that, not surprisingly.

CareFlight International Air Ambulance (CFIAA) is an ever changing beast, with our clinical teams and aircraft based in Darwin and Sydney. Over the journey we have also had aircraft in Perth and Cairns. Depending on where the team is on duty, they are most likely to be flying between Indonesia, East Timor, Papua New Guinea, Darwin and Adelaide (for Darwin crews) and Fiji, Noumea, Norfolk Island, Sydney and Brisbane if you are based in Sydney. Of course, it’s international so there actually isn’t a spot on the globe that shouldn’t be thought of as up for grabs.

Co-ordinators and Medical Directors sit behind the team at all times and, due to the miracle of mobile phones and the internet can be almost anywhere. Many of these folk never meet in person but are always looking over everybody’s shoulder.

More of that later, in this awe inspiring opening to the series I though I’d start with how it all gets going – who pays for it all?

The People with the Deep Pockets – Travel Insurers and Governments

When your average citizen takes out travel insurance, it is most likely to protect against such tragedies as losing an iPhone overseas, dropping a wallet in the ocean or perhaps finding himself in Vietnam and his luggage in downtown Boston. Having been in this game a while now, it is my opinion that if losing your iPhone is the worst thing that happens on your holiday you’ve had a pretty good time.

It may surprise you to know that a travel insurance policy is, by and large, a health insurance policy. Greater than 95% of the spend of travel insurance companies relates directly to health costs.

Each travel insurer has a series of service providers sitting behind them, one of which is an assistance company. There are a relatively small number of assistance companies that engage in this type of work. They have 24h call centres with co-ordinators, nurses and doctors (much like us).

In the event that John Q Citizen becomes unwell or is injured whilst they are away – by getting gored by a bull in Pamplona for instance – they or their relatives call the assistance company and a whole train of events unfolds, which might include directing patients towards local health care facilities to help with their medical problems.

The assistance company will maintain contact with the now patient and their family, and depending on how things in the event that the medical issue is of a serious nature, things tend to pan out in one of two ways that relate to the quality of health care available locally and the underlying urgency of the patient’s medical condition.

Let’s focus on the sicker end of the spectrum because clearly many issues are of a minor nature and never come anywhere near us.

If “definitive care” is available locally AND the quality of local medical care is high AND treatment of the matter is urgent assistance companies will usually head down the route of electing to keep the patient where they are for treatment in the theory that that is both (a) best for the patient and (b) cheaper than an international medical retrieval.

If “definitive care” is NOT available locally OR the quality of local medical care is questionable it is then the key decisions become urgency and mode of transport. There are, again, an array of transport options available but seeing as we are in the Air Ambulance business, again we might focus on that.

Send in the Big Bird

The assistance company, having decided that medical evacuation is required and that this is most appropriately by air ambulance asks its panel of Air Ambulance providers for a quote. At this stage, the available information usually consists of the patient location and their ultimate destination. No clinical information is available.

Our co-ordinator submits a quote, and due to the price of aviation fuel the retrieval company with the aircraft that has to do the least amount of flying to get the job done is usually cheapest. Paperwork is exchanged and the job confirmed.

Clinical information is then available and at this stage the CFIAA Medical Director is brought into the discussion – to liaise with treating clinicians at the hospital of origin as well as the destination unit. How many times is it quick and easy to have a chat with someone you’ve never met in the hospital? Well, it is fair to say that these conversations can be difficult – finding the right person in an overseas hospital at a sometimes odd times of day and surmounting the language barrier is not straightforward.

We are often going to locations where the quality of the medical and nursing staff are excellent but the broad array of diagnostic equipment that many of us consider routine are just not available. Similarly there are many locations where the patient will have a problem that is unable to be treated effectively with the resources available locally. It’s part of the game, and in many ways it’s why we are needed in the first place. A lot of the legwork for the coordinator is about trying to construct a story that is useful for the retrieval team and help plan for every contingency.

So, that’s a summary of all the things that happen before you get to find out about a case. We haven’t even got to the challenges of the actual patient yet.

I might finish off with a thought for the day:

If you can open your packs blindfolded, upside down and in a thunder storm – and know where everything will be, you have satisfactorily completed orientation.

Paediatrics

Scary Little Creatures

November 4, 2014 careflightcollective 12 Comments

Dr Andrew Weatherall does prehospital doctor stuff but spends lots of time serving the somnolent god of anaesthesia in a tertiary paediatric hospital. He has particular interests in cardiac, thoracic, trauma and liver transplant anaesthesia and is trying to be a PhD student in his spare time. You can also find him as @doc_andy_w

Little creatures have the potential to cause significant stress. It’s true of spiders. It’s true of parasites. And for many medicos, it’s true of paediatric patients. All too often, the experienced clinician confronted with the alien life-form of a kid goes through a rapid medical devolution, retreating to the almost foetal uselessness of a medical student confronted for the first time by having to do a procedure they’ve only read about.

Dance all you like tiny peacock spider, still wary. [via Jurgen Otto on Flickr under "Some Rights Reserved CC licence 2.0] — Dance all you like tiny peacock spider, still wary. [via Jurgen Otto on Flickr under “Some Rights Reserved CC licence 2.0]

It’s entirely reasonable to feel less comfortable with stuff you don’t do all the time. In fact, it’s healthy to step up a level of vigilance to make sure no little point in care is forgotten. The risk is that the heightened awareness can flip over to downright anxiety. Even experienced clinicians can sometimes forget that they are really good at what they are about to do and let little things compromise their success.

Managing the paediatric airway is a case in point. It is different. There are all those annoying calculations to remember. Everything feels the wrong size. The things that should be easy, like bag-mask ventilation, seem unusually clumsy. It’s as if someone managed to switch your shoes onto the wrong feet and then asked you to run.

When doing time in the paediatric theatres we frequently have experienced clinicians dropping by to brush up on their paediatric airway skills. From an observer’s point of view, there are little technical things that crop up repeatedly and cause grief. They are also the sort of technical hitches that distract from the mental process of getting the job done. If these little things were addressed, the prospect of the paediatric airway should be no more daunting than the prospect of participating in a yawning competition at the local retirement village lawn bowls competition.

So here, in no particular order, are the commonest practical things I see clever people forget:

A Light Touch

True paediatric patients are not big. Unlike the momentarily moribund wildebeest of adult medicine, they do not require brute strength. Airway management starts with good bag-mask technique and that should be easy (I am making the assumption that they don’t have the sort of condition that makes people widen their eyes when flicking through the ‘big book of syndromes’).

All too often those who do medical stuff in big people seem to want to subdue the small scruff of a paediatric patient with the big unwieldy shovels they refer to as ‘hands’. In smaller kids, it is really hard to apply good bag-mask technique if you try as you would in an adult, with a digit behind the angle of the jaw and other fingers arranged along the mandible.

Try this one – lay your middle finger gently across the soft tissue just where the neckline starts to head up to the chin (yep, right in the midline). Gently stretch the skin up to the jaw line with that middle finger (almost like you’re pushing the little ridge of skin up to the chin). Now add the mask with your index finger and thumb holding it to the face as per normal. You should have an open airway. That’s all the effort it takes (if that’s as clear as mud, let me know and I’ll try to produce a better version).

Puff

Smaller kids desaturate quickly. Whether or not you’ve done nasal prong oxygenation, you should feel at liberty to gently provide ventilations while waiting for the muscle relaxant to reach “apparent serenity now” efficacy.

Know Your Equipment

If you are going to use different equipment it pays off to know the details of the kit. This seems really obvious, but all too often the occasional paediatric airway specialist gets so focussed on the other bits of getting the job done they take the equipment stuff for granted and things get messy at some point after everyone thinks crunch time has been and gone.

Here’s an example. Observe the photo of two different kids endotracheal tubes. The one on the bottom is a bit more custom-designed for kids. Another popular brand up top looks pretty much like a down-sized adult endotracheal tube.

When you look closer, you might notice that the one on the bottom has an obvious black line where the tube is intended to line up with the cords. If you place it there, the tip of the tube is usually in a good spot, and the distance between cuff and cords is actually a fair bit.

Now look at the one on the top by comparison. The cuff ends around where that black line is. So if you place this one with the cuff a bit beyond the cords, you have successfully achieved lung isolation (kudos to you). Sometimes in bringing it back to where both lungs benefit from the cool breeze generated by your relieved bagging, the cuff could be sitting in the cords. Bugger.

OK, I flipped them but you can still see the different cuff position (and other features).

Knowing which one you carry (or should carry) matters. Same goes for choice of laryngoscope (and the resultant changes in positioning the patient). Speaking of which …

Keep an eye on the forest

You get handed a straight-blade laryngoscope to intubate a child (the fact that I’d probably choose a curved blade in pretty much every paeds patient is an entirely separate rant). Your job is to get a view on laryngoscopy that permits successful intubation. Your job is not to pick up the epiglottis. Do not confuse a popular choice for during the intubation with your daily KPI.

If placing the tip of the blade in the vallecula is what works, do that and put the tube in.

Use Cuffed Tubes

Shouldn’t we be choosing uncuffed tubes? Really? Just because you prefer harder to manage ventilation with a high chance of needing to change the tube entirely? Or are you a staunch supporter of tradition in medicine? Even where that tradition was established because the perished rubber endotracheal tubes with their low volume high pressure cuffs made of rubberised sandpaper were causing complications?

Seriously, just use cuffed tubes (and check the cuff pressure regularly). That way you get to do it just the once before the high fives rather than trying to figure out how to calibrate the ‘leak’.

Noses are for other doctors

There is no need for all endotracheal tubes in paediatric patients to be nose snorkels. A secure airway is the goal, and that is best done with a quick oral intubation. The number of doctors I see who seem to have the impression that neophyte airways means nasal airways in all circumstances never ceases to astonish.

So there’s just 6 quick tips to get the practical bits sorted. Is it absolutely exhaustive? No, but these are things I keep seeing (so you can grade the level of evidence as “stuff I see heaps and heaps that I thought I’d mention”). If you’ve got others (or disagree) I’m always all ears.

The aim is to help anyone get to the natural state of things – where ill kids needing intubation aren’t the scary ones. It’s healthy 3 year olds drinking red cordial at a party that inspire true fear.

Note:

This post is meant as a chance to share stuff seen through observation. If anyone is keen, I can follow up with the broader rant with the working title of “the variety of ways all that stuff about paediatric airways turns out to be kind of rubbish”, or the “choose the cuffed tube” rant in full.

Metamedicine

Who gets to tell the story?

August 13, 2014 careflightcollective 2 Comments

Medicine is a discipline built for the campfire. Or a theatre. Or for the gossip of the tearoom. We build knowledge and teams quicker with the stories we share than the papers we read.

This is particularly the case for prehospital and retrieval medicine. This is an area of medicine bordering different lands to hospital practice. Borderlands tend to be inhabited by strange beasts (and let’s be honest, a few strange people). Some of the situations we find ourselves in are unlikely to repeat themselves quickly and if we don’t hear the stories of those who have been there before, it’s a lot harder to be ready for some of those more colourful days at work. That’s partly what sites like this are about.

We also inhabit a time when sharing stories is easier than ever. Not only in the brilliant and stimulating FOAMed community either. Everyone wants to share their version of events. Everyone in the media. Everyone with a phone. This only makes it more vital to ask: who benefits from the stories we share?

Somewhere on a Road

This might be easier to think about using a case. A prehospital medical service is called to a road traffic accident. There’s just the one car involved with a 35 year old male unconscious at the scene and thought to have chest injuries. On scene there is a challenging extrication requiring assistance from the local firies. Before that though the decision is made to anaesthetise, intubate and mechanically ventilate while in the vehicle. The patient is thought to have a head injury but also has free fluid in the abdomen on ultrasound and the subsequent packaging and resuscitation during transport is worthy of plenty of discussion.

This would not be an unusual case but there is plenty that would make you want to talk about it. That chat would be most useful if it included details of the accident, an assessment of the injuries at the time, what was done and what the outcomes were. We’d all like to hear it.

Of course it might not just be the medical crews who want to spread the word. The prehospital service may well have an interest in telling the world of the work their teams are doing. That might be part of showing off what they do, or to promote important health messages.

The media, desperate to fill any available empty space with something other than coverage of plasticised reality show contestants shedding their dignity to secure a future in C-grade dinner theatre restaurants, will be all over it.

Those running media coverage may not meet the definition of 'super genius' [via thechive.com] — Those running media coverage may not meet the definition of ‘supergenius’ [via thechive.com]

Then there’s the potential for modern digital rubbernecking. It isn’t at all unusual to see numerous phones out recording footage of prehospital teams in action. By the time the team restocks the pack, that job may already be a fresh online instalment of very literal car crash TV.

All of these groups have something they feel they gain from sharing the story. Except for the patient of course. What do they gain? Not much that I can see. Which is why it’s only getting more important to do what we can to protect our patients from their stories spreading too wide.

Protecting our Patients

So extra care is probably needed in safeguarding their privacy, at least for the information that is in our control (media and bystanders add an extra level of complexity). The debrief after the job is one thing, but if you’re sharing cases for education or meeting purposes it seems like there’s a few obvious things to do:

1. Ask the patient

The best way to go about it is surely to seek permission from the patient wherever possible. The limits of what you can and can’t say will be clear and any discussion will be far better informed by knowing how the story developed for them.

2. Decide how much of the story is vital

This applies to any one of those players interested in telling the story. Plenty of good learning is still possible without every last detail.

3. Deidentify everything That should be obvious. There’s no need to retell identifying information but deidentification should extend further than that. For cases where you plan to present details in another forum or via other media, everything stored about that case should also be de-identified. I used to be more relaxed about what was stored electronically, but given alarming descriptions of the laxity of computer security from people who actually know stuff (like here), it’s safer to assume everything is always vulnerable.

4. Leave some things unsaid

Any time you share the story, even when from your perspective, you’re also sharing the patient’s story. So is the potential gain from the story, be it educational or any of the other potential benefits, enough to justify telling another’s story? There may be some cases where the potential risks of story details coming out make it much more important to suppress information.

What if that crash involves a kid? Would that change your approach to retelling the story, or letting the story get out to a wider audience?

What if the crash occurs because the car goes into a tree? The one tree on a long, straight stretch of road. Wouldn’t it be more important to protect the patient from their story potentially getting out into the community? Some stories should probably be left in place.

Perhaps I’m overthinking this. Maybe some would not see there being much risk when we share battle stories. But the more I think about the full range of responsibilities I have to the patient, the more I think I need to try and draw a line somewhere. The problem is the line keeps shifting on me.

This post came from Dr Andrew Weatherall who does prehospital medicine with CareFlight and kids anaesthesia most of the rest of the time. He also blogs over at http://www.theflyingphd.wordpress.com on stuff related to being a PhD student amongst other miscellany.

The Collective